SOLUTION: Man this one is a doozy it says, a cell phone company offers a contract for which the cost C, in dollars of t minutes of telephoning is given by C=0.25(t-600)+$61.95 where it is as

Algebra ->  Linear-equations -> SOLUTION: Man this one is a doozy it says, a cell phone company offers a contract for which the cost C, in dollars of t minutes of telephoning is given by C=0.25(t-600)+$61.95 where it is as      Log On


   



Question 248223: Man this one is a doozy it says, a cell phone company offers a contract for which the cost C, in dollars of t minutes of telephoning is given by C=0.25(t-600)+$61.95 where it is assumed t>600 minutes. What times will keep the cost between $110.45 and $134.70?
? minutes and ? minutes
Can someone please help? thanks so much

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Substitute C the two dollar amounts
and solve them
C=0.25(t-600)+$61.95
$110.45 and $134.70
let l=low time
and h=high time
11045=0.25(l-600)+6195
13470=0.25(h-600)+6195
Now solve the two equations separately for l and h and those will be low and high times